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P Fairchild

Publications and source records attributed to P Fairchild.

9 recordsLinked to original sources
PubMed2006

Investigation of the effect of a countywide protected learning time scheme on prescribing rates of ramipril: interrupted time series study.

BACKGROUND: Protected learning time (PLT) schemes have been set up in primary care across the UK. There is little published evidence of their effectiveness. OBJECTIVE: To investigate the effect of a PLT intervention for general practice to increase prescribing of ramipril for prevention of cardiovascular outcomes. DESIGN: Quasi-experimental, interrupted time series. SETTING: Lincolnshire, UK. METHODS: Prescribing data were analysed one year before and after the education for change in rate of increase of prescribing of ramipril, whether change in prescribing was related to postulated explanatory variables and to determine intervention costs. MAIN OUTCOME: The primary outcome was the rate of change of ramipril (10 mg) prescription items 12 months after compared with before the educational intervention. Secondary outcomes included cost. RESULTS: Ramipril prescribing at therapeutic dosage increased significantly (odds ratio 1.50, 95% CI 1.07-1.93) following education by 52,345 items (31,132 items at 10 mg) at a cost of pound 292k to pound 460k depending on formulation. This occurred despite a background of secular change. Most practices were represented by GPs, nurses or both during the education. Single-handed GPs were less likely to attend. Practices showed considerable variation in response to the educational intervention. The only predictor of whether practices increased in prescribing rate after the education was whether a practice nurse had undertaken specific diabetes training. Total list size, dispensing, training or single-handed status and GP attendance did not predict a change in prescribing. CONCLUSION: PLT schemes can contribute to beneficial changes in prescribing across a large geographical area.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2005

Regulatory T cells in transplantation tolerance.

Our ability to harness tolerance mechanisms will have a major impact in organ transplantation if it becomes possible to minimize drug maintenance, or even wean off immunosuppressive drugs. An improved understanding of the biology of regulatory T cells will make it possible to replace current induction regimens with those favouring the vaccination and selection of T cells that prevent graft rejection. Once tolerance is established, the continuous supply of graft antigens should sustain T cell mediated regulation as the dominant mechanism preventing graft rejection.

Animals↗
PubMed2002

Description and simulation of an active imaging technique utilizing two speckle fields: root reconstructors.

Quasi-monochromatic light will form laser speckle upon reflection from a rough object. This laser speckle provides information about the shape of the illuminated object. Further information can be obtained if two colors of coherent light are used, provided that the colors are sufficiently close in wavelength that the interference is also measurable. It is shown that no more than two intensities of two speckle patterns and their interference are required to produce an unambiguous band-limited image of an object, to within an overall spatial translation of the image, in the absence of measurement errors and in the case where all roots of both fields and their complex conjugates are distinct. This result is proven with a root-matching technique, which treats the electric fields as polynomials in the pupil plane, the coefficients of which form the desired complex object. Several root-matching algorithms are developed and tested. These algorithms are generally slow and sensitive to noise. So motivated, several other techniques are applied to the problem, including phase retrieval, expectation maximization, and probability maximization in a sequel paper [J. Opt. Soc. Am. A 19, 458 (2002)]. The phase-retrieval and expectation-maximization techniques proved to be most effective for reconstructions of complex objects larger than 10 pixels across.

Journal Article↗
PubMed2002

Description and simulation of an active imaging technique utilizing two speckle fields: iterative reconstructors.

Quasi-monochromatic light will form laser speckle upon reflection from a rough object. This laser speckle provides information about the shape of the illuminated object. In a prior paper [J. Opt. Soc. Am. A 19, 444 (2002)], it was shown that two intensities of two speckle patterns and their interference are sufficient to produce an unambiguous (except for object translation) band-limited image of the object, based on a root-matching technique described therein, in the absence of measurement error and in the case of distinct roots of the field polynomials and their complex conjugates. On the other hand, algorithms based on the root-matching technique are found to be slow and sensitive to noise. So motivated, several other techniques are applied to the problem, including phase retrieval, expectation maximization, and statistical maximization. The phase-retrieval and expectation-maximization techniques proved to be most effective for reconstructions of complex objects larger than 10 pixels across, and high-quality images were formed by using three independent sets of two-field data (three frames of two-wavelength data), each comprising two speckle intensity patterns and their interference. Two additional results of note are reported. First, the expectation-maximization algorithm produced relatively good images when three or more frames each of only one speckle intensity pattern (data at just one wavelength) were used and second, the phase-retrieval algorithm when only the object autocorrelation was used also produced relatively good images for the chosen test object.

Journal Article↗
PubMed2001

Therapeutic aspects of tolerance.

The immune system is naturally unresponsive to 'self' antigens. Improved knowledge of mechanisms underlying self tolerance is giving rise to a new generation of immunosuppressive agents, that can exploit these mechanisms and so reduce the nature and level of medication that needs to be given long-term to control diseases where the immune system does harm.

Animals↗